共查询到20条相似文献,搜索用时 437 毫秒
1.
Eike Kirchner Frauke Thiem Rudolt Dernick Jochen Heukeshoven Joachim Thieina 《Journal of carbohydrate chemistry》2013,32(2):453-486
Abstract Glycal derivatives of N-acetylneuraminic acid were prepared and their N-iodosuccinimide-mediated glycosylation shown to proceed only with most reactive alcohols, Their reduced enol ether reactivity is attributed to the α unsaturated ester reature. Thus several reduced glycal derivatives were synthesized. These couid be glycosyiatec with simple alcohols as well as otner saccnarides as aglycones in averaae to modest yields with the trans-diaxiai additions compounas prevailing. A number or selective and specific prepparation led to both the anomeric phenylthioglycosides or N dcety Ineuraminic acid. These could be used in phenylmercurl triflate-promoted glycosylations to afford several derivatives. 相似文献
2.
Abstract MePh3P+BH4 ? is able to reduce aldehydes and ketones to their corresponding alcohols in CH2Cl2. Aldehydes are reduced with high selectivity in the presence of ketones. α,β-Unsaturated carbonyl compounds undergo 1,2-reduction and produce their corresponding allylic alcohols in high yields. Carboxylic acid chlorides are also converted to their alcohols with high yields. 相似文献
3.
《合成通讯》2013,43(9):1177-1182
Abstract Bismuth(III) triflate has been found to be an efficient catalyst for the Prins reactions of styrenes and homoallyl alcohols, the reaction proceeds rapidly and affords the corresponding 1,3‐dioxanes and tetrahydropyran‐4‐ol in good yields. Scope and limitations of the styrenes and homoallyl alcohols are reported. 相似文献
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The preparation of novel 3-, 4-, 6-, and 13-amino-tetradecanoic acid methyl esters (2a–d) obtained by the reduction of 3-, 4-, 6-, and 13-oximino-tetradecanoic acid methyl esters (1a–d), was investigated. Oximino esters were reduced to afford the corresponding amino esters using NaBH4–ZrCl4 reducing system with good yields (58–82%). However, the reduction of oximino esters with LiAlH4 and BH3. Tetrahydrofuran gave the corresponding novel 3-, 4-, 6-, and 13-oximino alcohols (3a–d), and 3-, 4-, 6-, and 13-amino alcohols (4a–d) respectively with good chemical yields. 相似文献
5.
Abstract An effective and reusable catalytic system for the oxidation of alcohols was developed based on ?-Na8HPW9O34. The oxidation was conducted in water using hydrogen peroxide as oxidant. Good yields of ketones were obtained in oxidation of secondary alcohols, and the catalyst was recycled 10 times without obvious loss in activity. 相似文献
6.
A new type of sulfoxide, 4-(2-(2-(methylsulfinyl) ethyl)-4-nitrophenyl)- morpholine (I), was designed and prepared in good yield. Upon the combination of I and bis(trichloromethyl)carbonate, the Swern oxidation of primary and secondary alcohols was significantly promoted under mild conditions, which afforded the corresponding aldehydes or ketones in good yields. It is noteworthy that the reoxidation of the isolated by-product sulfide V could be further recycled in Swern oxidation. 相似文献
7.
An efficient and convenient new method has been developed for the preparation of haloallenes from propargyl alcohols by a reagent combination of N-halosuccinimide and triphenylphosphine. Chloroallenes 2 and bromoallenes 3 were obtained exclusively in moderate to good yields with regioselectivity. 相似文献
8.
《合成通讯》2013,43(19):3473-3480
Abstract The use of the Barbier‐Grignard reaction, where premixed allyl bromide and the carbonyl compound are added to magnesium in ether, is reported for the synthesis of homoallylic alcohols. This reaction provides good to excellent yields of most homoallylic alcohols with minimal formation of Wurtz coupling products. 相似文献
9.
Jincheng Mao 《合成通讯》2013,43(20):3710-3721
A series of chiral sulfamide–amine alcohols (SAA) (1–6) has been easily synthesized from commercially available chiral amino alcohols. In the absence of Ti(O i Pr)4, ligand 4 catalyzed the asymmetric addition of diethylzinc to aromatic aldehydes with moderate to good yields and enantioselectivities. 相似文献
10.
《合成通讯》2013,43(21):3671-3677
Abstract Structurally different benzylic alcohols were efficiently converted to their corresponding chlorides by silica chloride (SiO2-Cl) in CHCl3 at room temperature. Silica chloride is also able to convert benzylic alcohols to their iodides in the presence of NaI in a mixture of CH3CN/CHCl3 in excellent yields. 相似文献
11.
Exnantiocontrolled reduction of prochiral ketones with borane in the presence of homochiral amino alcohols 1 - 4 as enantioselective catalysts afforded the chiral corresponding secondary alcohols in moderate to high (55 to 88 %) optical yields. 相似文献
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Enantiocontrolled reduction of prochiral ketones with borane in the presence of homochiral amino alcohols 1—3 as enantioselective catalysts afforded the corresponding secondary alcohols in moderate to high (69 to >99 %) optical yields. 相似文献
15.
《合成通讯》2013,43(21):3263-3271
ABSTRACT Regio- and stereoselective radical addition of α-allenic alcohols with p-TsBr in the presence of a catalytic amount of AIBN afforded (E)-γ-bromo-β-sulfonyl allylic alcohols in moderate yields. The base-promoted 1,4-elimination followed by isomerization to give β-sulfonyl-α,β-unsaturated ketones is described. 相似文献
16.
Enantiocontrolled reduction of prochiral ketones with borane in the presence of new enantiomerically pure bi-and tricyclic β-sec-amino alcohols 2–5 as stereodifferentiating catalysts afforded the optically active corresponding secondary alcohols in moderate to excellent (up to 98 % op) optical yields. 相似文献
17.
Tülay Yildiz 《合成通讯》2018,48(17):2177-2188
An efficient organocatalytic route has been developed to synthesize novel substituted thioxanthenes (2a–2v) starting from diaryl thioether alcohols (1a–1v) using the intramolecular Friedel–Crafts reaction. The starting materials were obtained in two stages via a coupling reaction followed by the Grignard reaction. In this study, we tried for the first time to use some organic Brønsted acids as organocatalysts (3a–3h) in the intramolecular Friedel–Crafts cyclization reaction of thioether alcohols. The synthesis of original substituted thioxanthenes was achieved within 15?minutes by using N-triflylphosphoramide (3h) with quantitative yields in THF at room temperature. 相似文献
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AbstractPalladium catalyzed intermolecular 1,2-addition of arylboronate to unactivated ketone was investigated. NHC-coordinated palladacycle 4c exhibited catalytic activity for the reactions and provided the corresponding tertiary alcohols and γ,γ-disubstituted γ-lactones in good to excellent yields. 相似文献
20.
Ryosuke Ohmura 《Tetrahedron letters》2010,51(33):4378-1387
Various primary alcohols, particularly benzylic alcohols, could be converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq. NH3, followed by reaction with ∼30% aq H2O2. Similarly, various benzylic halides could be also converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq NH3, followed by reaction with ∼30% aq H2O2. The present reactions involve the metal-free one-pot oxidative conversion of benzylic alcohols and benzylic halides into the corresponding aromatic amides, respectively. 相似文献